Some earth-boring tools for forming boreholes in subterranean formations, such as, for example, fixed-cutter earth-boring rotary drill bits (also referred to as “drag bits”) and reamers, include cutting elements secured to the rotationally leading portions of blades. The cutting elements are conventionally fixed in place, such as, for example, by brazing the cutting elements within pockets formed in the rotationally leading portions of the blades. When the cutting elements are fixed, only a portion of a cutting edge extending around a cutting face of each cutting element may actually engage with and remove earth material. Because earth removal exposes that portion of the cutting edge to highly abrasive material, it gradually wears away, which dulls that portion of the cutting edge and forms what is referred to in the art as a “wear flat.” Continued use may wear away that portion of the cutting edge entirely, leaving a completely dull surface that is ineffective at removing earth material.
Some attempts have been made to induce each cutting element to rotate such that the entire cutting edge extending around each cutting element engages with and removes earth material. For example, U.S. Patent Application Pub. No. 2008/0017419, published Jan. 24, 2008, for “CUTTING ELEMENT APPARATUSES, DRILL BITS INCLUDING SAME, METHODS OF CUTTING, AND METHODS OF ROTATING A CUTTING ELEMENT,” the disclosure of which is incorporated herein in its entirety by this reference, discloses rotatable cutting elements that are actively rotated using a cam assembly. As another example, U.S. Pat. No. 7,703,559, issued Apr. 27, 2010, for “ROLLING CUTTER,” the disclosure of which is incorporated herein in its entirety by this reference, discloses cutting elements that are passively rotated within support elements that may be brazed to the blades of a drill bit.